Microbiology Flashcards
Antibiotics inhibiting DNA synthesis
Ciprofloxacin
Metronidazole
Sulphonamide
Trimethoprim
Antibiotics inhibiting RNA synthesis
Rifampicin
Antibiotics inhibiting protein synthesis
macrolides—erythromycin,clarithromycin
Infection related with watercress eating
Fasciola hepatica
Site of fasciola hepatica maturation
Within bile duct during chronic phase
Symptoms of chronic phase of fasciola hepatica infection
Intermittent pain
Anemia
Treatment of fasciola hepatica
Triclabendazole / ERCP
Prodromal phase time of infection with clostridium perfringens
Several hours later
Food poisoning from wedding may cause by Which organism and why
Clostridium perfringens due to resistance to boiling
Type of staphylococcus aureus
Facultatively anaerobic
Gram positive
Catalase positive
Causing haemolysis on blood agar
Most common cause of cuteneous infection
Staphylococcus aureus
Because 20% of population is long term carrier
Bacterial cause of endocarditis
Streptococcus bovis
Bacterial related with septicemia with carcinoma of colon
Streptococcus bovis
Infection of native cardiac valve caused by Which organism
Streptococcus viridens
Infection of prosthetic cardiac valve caused by Which organism
Staphylococcus epidermidis
What would happen to testes during Fourier gangrene
Spared
It only involves skin and fascia
Causative organism of Fournier gangrene
E coli
Bacteroides
Meleney’s gangrene
Necrotising fascists of trunk
Where we can find dirty dish fluid discharge
In necrotising fascitis
Common cause of bacterial diarrhea in immunocompromised patients
Cryptosporidium
Relation of clostridium deficile with antibiotics
It may infect after irresponsible administration of broad spectrum of antibiotics
Clinical feature of clostridium deficile
Pseudomembranous colitis
Yellowish black plaque over damaged epithelium
Type is vibrio cholera
Short comma shaped gram negative rod
Manifestation of cholera
Sudden onset of effortless vomiting and profuse watery diarrhoea
Management of cholera
Correction of fluid and electrolytes imbalance
Bacterial cause of Hospital acquired watery diarrhoea
Clostridium deficile
Risk of Which infection may be increased by use of broad spectrum antibiotic
Clostridium deficile
Route of spread of clostridium deficile
Feco oral
Inhalation of spores
Type of enterobius vermicuilaris
Pin worm
Which worm may cause iron deficiency anemia
Ancylostoma duodenale
Treatment of diarrhoea by giardia
Metronidazole
Treatment of cryptographic
Metronidazole
TPN associated liver disease
Painless jaundice(non calcular, non obstructive)
Fatty liver
Hepatic dysfunction
Due to long time use of TPN
Charcot’s triad indicates what
Cholingitis
E coli causing in children but adult
Hemolytic uremic syndrome
Relation of revascularization with amputation
Never amputate before trying revascularization
Treatment of amebic liver abscess
Metronidazole
Treatment of hydatid cyst
Mebendazole
Never wait for fluctuation test to be positive in abscess
Breast
Parotid
Palm/fingertip
Perineal
Abscess must be aspirated
A amebic
B brain
C cold
Alpha streptococcus
Pneumoniae
Viridens
Group B beta streptococcus
Agalactica
Group A beta streptococcus
Pyogens
Disease by alpha streptococcus
Pneumonia, meningitis, otitis media
Disease by group B beta streptococcus
Neonatal meningitis & spticemia
Disease by group a beta streptococcus
Erysipelas cellulitis
Type 2 necrotising fascitis
Pharyngitis
Tonsillitis
Which streptococcus may cause glomerulonephritis
Group A beta
rheumatic heart disease related streptococcus
GAS (group A streptococcus)-pyogens
Cause of scarlet fever
GAS by erythrogenic toxin
Action of macrolides
Inhibits bacterial protein synthesis
Macrolides bind to the 50S ribosomal subunit of bacteria, PREVENTING the TRANSLATION of mRNA and the addition of amino acids to the growing peptide chain. This makes them bacteriostatic, but at high doses they can be bactericidal.
Adverse effect of erythromycin
GI upsets
Cholestatic jaundice
Inhibiting P450 enzyme
Diagnosis of fasciola hepatica
Stool sample
Serology
Also USG finding of intraluminal parasites
State of worn during acute phase of fasciola hepatica
Immature worms begin to penetrate gut
Skin change during fasciola hepatica infection
Rash in acute phase
Site of maturation of fasciola hepatica
Bile duct
CBC of chronic phase of fasciola hepatica
Anaemia
Time for symptoms of infection with clostridium perfringens and what symptoms with rival sooner infective manifestation
Several hours
Food poisoning
Rival is staphylococcus aureus
Basis of large volume fluid in stool in Ecoli
Enterotoxin ST by enterotoxigenic E coli view cyclic gAMP
Association of septicemia with streptococcus bovis
Carcinoma colon
Endocarditis
Antibiotic for campylobacter jejuni
Not routinely advised but
Quinolones are very effective
(nalidixic acid, ciprofloxacin, levofloxacin and moxifloxacin.)
Pathogens for necrotizing fasciitis
Mostly polymicrobial -Both aerobic +anaerobic
Ecoli (with/out O2)
Bacteroides (without O2)
Isolated streptococcus 15% cases
Opportunist diarrhoeal infection
Cryptorchidism mostly
Salmonella
Shigella
Campylobacter
Raid spread of diarrhea in hospital by which organism
Clostridium defficile
Vascular involvement of syphilis
Involves proximity aorta causing aneurysm
Infective cause of hard painless groin ulcer
Treponema pallium
What is gumma lesion
Diffuse lymphadenopathy in tertiary syphilis
Why visualize actinomyces and to see what to diagnose
Culture is difficult
To see sulphur granules
feature of actinomycosis
Sulfur granules are a characteristic feature of actinomycosis, a rare bacterial infection that causes painful abscesses and tunneling wounds
What they are and Why they are called sulfur granules and What they indicate
Sulfur granules are clumps of immune cells and bacteria that appear in the pus from actinomycosis abscesses.
They are named for their yellow appearance, but can also be white, gray, or brown.
The presence of sulfur granules indicates a granulomatous and suppurative infection
What is Actinomycosis with treatment
Actinomycosis is caused by the bacteria Actinomyces, which infects by reducing oxygen levels and inhibiting the body’s defenses. The most common types of actinomycosis are cervicofacial, pulmonary, and abdominal.
High doses of intravenous penicillin, followed by oral penicillin
Surgical drainage of abscesses
Excision of sinus tracts
Removal of infected masses
Which parasite can cause surgical jaundice
Ascaris
Which parasite can cause intestinal obstruction
Ascaris
Basis of prehepatic jaundice
Conditions increasing hemolysis
Other name of posthepatic jaundice
Obstructive
Surgical
Direct jaundice
conjugated jaundice
water soluble bilirubin
excreted in urine (dark yellow)
So positive urinalysis
Symptoms by O157 E coli
Hemorrhagic colitis
Hemolytic uremic syndrome (children)
TTP
Disease by EBV
Hodgkin’s lymphoma
Burkitt’s lymphoma
Post transplant lymphoma
Nasopharyngeal carcinoma
Infection with pungent aroma caused by
Bacteroides
is bacteroides part of gut Flora
Yes, Bacteroides is a common part of the human gut flora:
Abundance: Bacteroides make up about 25% of the intestinal microbiota.Bacteroides are a dominant microflora in the human gut.Bacteroides are found in the gut, mouth, upper respiratory tract, and genital tract.
Importance of bacteroides in surgery
Bacteroides can cause serious infections if they spread to the bloodstream or surrounding tissues from normal GUT Flora.This can happen if the mucosal surface is disrupted by inflammation, trauma, or SURGERY.
Incubation period of HBV
6-20 weeks
Examples of antivirals for HBV
Lamivudine
Tenofovir
Entecavir
Cornerstone of treatment of necrotizing fasciitis
Thorough debridement
Antibiotic for cellulitis
Penicillin
If by group A beta hemolytic streptococcus pyogenes
Type I and type II necrotizing fasciitis differ
Type I and type II necrotizing fasciitis differ in the type of bacteria that causes the infection, the risk factors, and the patient profile:
Type I
Also known as POLYmicrobial necrotizing fasciitis, this type is caused by a mix of aerobic-Ecoli and anaerobic-bacteroides bacteria. It’s most common after surgery, in people with diabetes, or in those with peripheral vascular disease. Patients with type I necrotizing fasciitis are often immunoCOMPROMISED.
Type II
Also known as MONOmicrobial necrotizing fasciitis, this type is usually caused by group A streptococcus pyogenes or Staphylococcus aureus. It can occur after surgery, from penetrating trauma, varicella infection, burns, or minor cuts. Patients with type II necrotizing fasciitis are usually immunoCOMPETENT and have a history of trauma.
Immunolocal reactive streptococcus
GAS (group A streptococcus)
like Pyogenes
Causing-
PSGN
Rheumatoid fever
which GAS cause scarlet fever
Pyogenes
Disease by group B beta hemolytic streptococcus
Neonatal meningitis
Septicemia
—by agalactica
A biofilm composition and function
A biofilm is defined as a community of microorganisms attached to an inert or living surface by a self-produced polymeric matrix or an assemblage of microbial cells associated with a surface and enclosed in a matrix of primarily polysaccharide material.
Why is Clostridium difficile resistant to antibiotics?
Antibiotic resistance in C. difficile has a multifactorial nature. Acquisition of genetic elements and alterations of the antibiotic target sites, as well as other factors, such as variations in the metabolic pathways and biofilm production, contribute to the survival of this pathogen in the presence of antibiotics.
what to use to kill difficile
Antibiotics and disinfectants (chlorine bleach,hydrogen peroxide) are used to treat and kill Clostridioides difficile (C. diff) infections and spores, respectively
main treatment for C. diff infections
antibiotics, such as metronidazole, vancomycin, and fidaxomicin. The type of antibiotic prescribed depends on the severity of the infection. BUT IF the infection is CAUSED BY antibiotics, a healthcare provider may stop the patient from taking them.
Relation of clostridium with oxygen
C. diff spores die when they come into contact with oxygen.
relation of broad spectrum antibiotics with C. difficile
Most antibiotics, including broad-spectrum antibiotics meant to target a wide range of microorganisms, are ineffective against C. difficile.
Which infection causes pseudomembranous colitis
Clostridium difficile
Symptoms of Pseudomembranous colitis
Abdominal pain, diarrhea, fever, nausea, bleeding or PUS in stool
Basis of pseudomembranous colitis
Enterotoxin of clostridium difficile
Risk factors of pseudomembranous colitis
Use of broad spectrum antibiotics
Contact with person infected with Clostridium difficile
Use of PPI/H2 receptor blockers
Diagnosis of pseudomembranous colitis
Stool for enterotoxin of C. difficile
WBC in stool (due to pus)
TLC raised in CBC
Which organism may cause toxic megacolon
C. difficile
Patient complaining about diarrhea and abdominal bouts at different site after taking broad spectrum antibiotics
What is the cause?
Clostridium difficile
Treatment of clostridium difficile
1st line -oral metronidazole 10-14 days
If Non-responder add
Oral vancomycin
If not working add
Oral fidaxomicin
Surgical relation with clostridium difficile
Severe unremitting colitis may need surgical resection
chlorination resistant protozoa
Giardia
Which protozoal infection will cause greasy stool
Giardia
Most common cause of septic arthritis with exception
Staphylococcus aureus
In sexually active person neisseria gonorrhea may be considered
Treatment of septic arthritis
Decompress the joint by aspiration it even by arthroscopic lavage then antibiotic
Antibiotics for septic arthritis and route
IV antibiotics
Penicillin
But if allergic to it then—
Flucloxacillin
Clindamycin
For 6-12 weeks
Diarrhea cause after eating Bird pecked food
Campylobacter jejuni
Organism colonizing prosthetic plastic device
Staphylococcus epidermidis
Common causes of osteomyelitis and exception with sickle cell
Staphylococcus aureus most common
Also
Enterobacter
Streptococcus
In sickle cell disease by salmonella (S-S)
why salmonella causes osteomyelitis in sickle cell disease and treatment
Gut damage by Sickle cell allows salmonella to enter the bloodstream more easily.
SCD reduces the immune system’s ability to clear bacteria from the bloodstream.
The expanded bone marrow provides a place for salmonella to hide and grow. In other words The expanded bone marrow with sluggish flow leads to an ischemic focus for salmonella localization.
Repeated thrombosis of vessels in bones makes it harder to achieve high concentrations of antibiotic in the infected areas.
Treatment
Chloramphenicol, ampicillin, and trimethoprim/sulfamethoxazole are commonly used, but newer beta lactams and quinolones are more active.
Imaging of osteomyelitis
Early MRI (cause X-ray inefficient)
Late X-ray revealingly lytic lesion with sclerotic periphery
Manifestation of HIV serocoversion
Glandular fever type illness
Feature of serocoversion of HIV
Sore throat
Lymphadenopathy
Myalgia
Arthralgia
Diarrhea
Maculopapular rash
Oral ulcer
Meningoencephalitis rarely
Time fire HIV serocoversion and diagnostic tools
3-12 weeks
HIV PCR & p24 antigen are positive
HIV antibody may still not appear
Confirmatory test for HIV
Western blot for detecting antibody
Which tests are use to detect HIV antibody and most probable time to be positive
ELISA
Western blot
Antibodies start to appear within 4-6wks
99% cases are positive after 3 months
Reynolds pentad is related to with disease
Cholangitis
Which bacterial screening is needed during hospital admissions to prevent hospital acquired infection
MRSA
Procedure to screen MRSA and caution
Nasal swab for 5 seconds
Wound swab
Caution: level the specimen container with MRSA screen to prevent poor handling
Suppressing process of MRSA carrier
Nasal mupirocin 2% for 5 days
Skin chlorhexidine applied all over particularly at axilla,groin,perineum for 5 days
Treatment of MRSA
Vancomycin
trimethoprim-sulfamethoxazole
tetracyclines
Newer (reserved as last resource)
Linezolid
Dalfopristin +quinupristin
Most common cause of generalized lymphadenopathy with splenomegaly and even spontaneous rupture of spleen
EBV
Complications is acute pancreatitis
Hypoxia -due to ARDS by microthrombi into pulmonary vessels
Hypocalcemia -by sequestration of calcium in fat necrosis
Hypoalbuminemia - increased capillary permeability
But
Hyperglycemia -disruption of pancreatic islets
All of above with result in—
Shock -body can become dehydrated
&
Adrenal failure-Severe acute pancreatitis can cause extensive tissue destruction in the retroperitoneum, which can damage the adrenal glands or reduce blood flow to them
Fluid leak in pancreatic bed with fluid filled ileus will lead to pre renal azotemia which may lead to acute tubular necrosis if remains untreated
(Prerenal azotemia is a condition where the blood has abnormally high levels of nitrogen waste products)
Cause of fat necrosis in acute pancreatitis
Increased lipase activity on triglycerides
Reason of hypoproteinemia in acute pancreatitis
Loss of plasma in peritoneal space
Cause of tachypnea of a diabetic patient during surgery
Hypoglycemia
Neutrophilia in CSF
Bacterial infection
Lymphocyte predominant CSF
Viral infection
Which liver disease may cause hypotension and confusion and its importance
Cholangitis
Surgical emergency to facilitate bile drainage
